Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ACM-ICPC mode for virtual contests.
If you've seen these problems, a virtual contest is not for you - solve these problems in the archive.
If you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.
Never use someone else's code, read the tutorials or communicate with other person during a virtual contest.

Sereja is interested in intervals of numbers, so he has prepared a problem about intervals for you. An interval of numbers is a pair of integers [l, r](1 ≤ l ≤ r ≤ m). Interval [l1, r1] belongs to interval [l2, r2] if the following condition is met: l2 ≤ l1 ≤ r1 ≤ r2.

Sereja wants to write out a sequence of n intervals [l1, r1], [l2, r2], ..., [ln, rn] on a piece of paper. At that, no interval in the sequence can belong to some other interval of the sequence. Also, Sereja loves number x very much and he wants some (at least one) interval in the sequence to have li = x. Sereja wonders, how many distinct ways to write such intervals are there?

Help Sereja and find the required number of ways modulo 1000000007(109 + 7).

Two ways are considered distinct if there is such j(1 ≤ j ≤ n), that the j-th intervals in two corresponding sequences are not equal.

Input

The first line contains integers n, m, x(1 ≤ n·m ≤ 100000, 1 ≤ x ≤ m) — the number of segments in the sequence, the constraints on the numbers in segments and Sereja's favourite number.